Hose fittings for cruising in France (and Europe?)

This note is about a seemingly trivial, yet surprisingly important, topic - what hoses and hose fittings should be aboard a boat cruising in Europe? 

When Katy and I started cruising aboard Idril, we had a two collapsible hoses and a slightly-broken spray nozzle, all brought from the U.S. in the pallets of boat stuff we shipped before Idril was complete. We immediately discovered that the U.S. hose connectors are not QUITE the same as the (metric) hose connectors in France and England, and so they leaked when we tried to use them. 

To remedy this, we visited Jardiland, "up the hill" in Cherbourg.There we discovered the Gardena hose fitting system.This system allows hoses and accessories to be easily connected and disconnected with a simple push-pull action.  There's a huge variety of fittings available, and we soon had:

• A replacement for the collapsible hose that we brought from the U.S. and a shiny new multi-setting spray nozzle.
  
  
  
  
  
• A more substantial hose that we reserve primarily for filling our water tanks; we only use it with water supplies we consider fairly clean.
• A two-stage water filter gizmo that we use to filter all of the water that goes into our fresh water tanks, regardless of source.
  
  
  
  
  
• Various connectors and spares.
  
  
  
  
  

I also purchased a short length of good quality hose that I can use to construct a "U.S. to Gardena" adapter, once we get to the U.S. and have access to U.S. hose fittings.

These fittings got us through most of the summer 2021 cruising season.Most marinas provide conventional screw-type faucets (for which we had the fitting); some provide a permanently-attached hose with a bare end, into which I could insert a "bare hose to Gardena" fitting.

Upon arrival in Roscoff, in mid August 2021, we encountered yet another variation -- the "Gardena only" tap. This has a female Gardena fitting, and the flow of water starts (ready or not...) as soon as you insert a male Gardena fitting into the tap.

Luckily, we had just the fitting, and a valve fitting for the business end of the hose. Hooray!

Here's the crucial subset.